William matheb



(No Model.) W. MATHER.

BXPANSIBLE AND OOLLAPSIBLE SCREW TAP. No. 387,431. Patented Aug. 7.1888.

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\VILLIAM MATHElt, OF NEW YORK, N. Y.

SPECIFICATION forming part of Letters Patent No. 387,431, dated August7, 1888.

Application filed May 12, 1888.

To all whom, it may concern.-

Be it knownfithat I, WILLIAM MATHER, of the city, county, and State ofNew York, have invented a new and Improved Collapsing and ExpandingScrew-Tap, of which the following is a full, clear, and exactdescription.

My invention relates to an improvement in collapsing and expandingscrew-taps, and has for its object to provide a means whereby thecutting-dies may be effectually and expeditiously projected outward ordrawn inward, so that when the screw-thread has been out the dies may beso manipulated as to enable the tap to be Withdrawn without thenecessity of a reverse rotary movement for that purpose.

The invention consists in the construction and combination of theseveral parts, as will be hereinafter fully set forth, and pointed outin the claims.

Reference is to be had to the accompanying drawings,forming a part ofthis specificatiomin which similar letters of reference indicatecorresponding parts in all the figures.

Figurel is a side elevation. Fig. 2 is a plan verse section on linex xof Fig; 1. Fig. 4 is a longitudinal section on line y y of Fig. l, andFig. 5 is a central transverse section.

In carrying out the invention the casing consists of a hollow mandrel,A, provided at the cutting end with longitudinal slots or seats for thecutting-dies B. A spindle, O, is adapted to turn in the hollow of saidmandrel,provided at the lower end with a cam, D, consisting of thereduced extremity cl, and spaced longitudinal wings d, radiatingtherefrom. The saidcam D is produced by forming longitudi' nal undercutgrooves,whereby a shoulder, 2, is obtained, having a cam-face adapted toforce the dies outward, a re-entering inclined surface, 3, and theessentially V-shaped recess 4, the outer wall of which is adapted toengage the lip of the die, hereinafter described, and draw the sameinward. The periphery of the spindle intervening the under-cuts, andwhich constitutes the outer surface of the wings d, is shaped to snuglyfit the bore of the mandrel. The lower extremity, d of the spindle isreduced and adapted to extend beyond the mandrel.

A longitudinal lip, b, is produced upon one inner side of the dies B,the inner surface of Serial No. 2713,6805. (No model.)

said dies being concaved to lit the convex inner wall of the V-shapedrecess 4, and likewise the shoulder 2 of the cam, when the dies arerespectively thrown outward and drawn inward, as best shown in Figs. 2and 3.

The inner edge of the dies is inclined outward in direction of thesmooth face, which inclination is purposed to correspond with thereentering inclined surface 3 of the cam when the dies are drawn in, asshown in Fig. 8, and the similarly-inclined surface 5 of the camextending outward from the shoulder 2 to the outer cylindrical surfaceof the wings when the dies are thrown outward, as best shown in Fig. 3.

The spindle is provided with a threaded aperture, E, at or about thecenter, and in the mandrel opposite the said spindle-aperture adiametrical slot, E, is produced. The spindle is reciprocated throughthe medium of a sectional handle, one of which, section e, is providedwith a reduced exteriorly-threaded end adapted to enter the mandrel-slotat one side, pass through the spindle-aperture, and project beyond theopposite side of the mandrel. The section e is provided with a threadedlongi tudinal bore to receive the proj ecting threaded endof the section6, as best shown in Fig. 5.

Beaming-dies H are located in the forward or cutting end of the mandrelbetween the several dies 13, and the dies when inserted in thelongitudinal slots or seats of the mandrel and into the under-cuts ofthe cam are retained in position by a cap-plate, H, apertured to receivethe reduced end of the spindle and likewise suitable screws, whichlatter are entered into the lower edge of the mandrel.

In operation,to expand the dies the handlesections are turned to theright,whereupon the spindle revolving in that direction causes theconcave surface of the dies to ride up upon the cam face of theshoulders 2 and the inclined surface of the dies to bear against theinclined faces 5 of the earn, as illustrated in Fig. 2. WVhen the handleis turned in the opposite direction, the V-shaped recess is broughtopposite the die seats or slots, and the said dies are drawn inward andseated in the said recesses by the engagement with the outer face of thelip of the wings d or the outer wall of recess 4, as best shown in Fig.3.

Having thus described my invention, what I claim as new, and desire tosecure by Letters l mandrel in engagement with the cam, substan- Patent,is

1. The combination, with the lipped cutting-dies, of a winged cam foradjusting the said cutting'dies inwardly and outwardly, substantially asshown and described.

2. The combination, with a mandrel and a spindle rotating in the sameprovided with a winged cam at one end, of lipped cutting-dies held insaid spindle, said dies being carried outward and inward by said cam,substantially as shown and described.

3. The combination, withamaudrel, aspindle rotating in the same, awinged cam integral with one end of said spindle, and a sectional handlepassing through the spindle and mandrel, of lipped cutting-dies held inthe tially as shown and described.

4. The combination, with a mandrel and a spindle held to rotate in thesame provided with aseries of longitudinal under-cuts in the cutting endforming the cam-shoulder 2, the reentering inclined surface 3, theV-shaped recess 4, the inclined surface 5, and the Wings d, of cuttingdies held in the mandrel provided with a longitudinal lip upon one sideand having inclined and concaved inner edge, substantially as and forthe purpose specified.

C. SEDGWICK, EDWD. M. CLARK.

